Laszlo Demko

• PhD
• PostDoc Position at ETH Zurich

Most established clinical walking tests assess specific aspects of movement function (velocity, endurance, etc.) but are generally unable to determine specific biomechanical or neurological deficits that limit an individual’s ability to walk. Recently, inertial measurement units (IMU) have been used to collect objective kinematic data for gait anal...

Background An incomplete spinal cord injury (SCI) refers to remaining sensorimotor function below the injury with the possibility for the patient to regain walking abilities. However, these patients often suffer from diverse gait deficits, which are not objectively assessed in the current clinical routine. Wearable inertial sensors are a promising...

Background Gait speed is a widely used outcome measure to assess the walking abilities of children undergoing rehabilitation. It is routinely determined during a walking test under standardized conditions, but it remains unclear whether these outcomes reflect the children's performance in daily life. An ankle-worn inertial sensor provides a usable...

Neurorehabilitation is progressively shifting from purely in-clinic treatment to therapy that is provided in both clinical and home-based settings. This transition generates a pressing need for assessments that can be performed across the entire continuum of care, a need that might be accommodated by application of wearable sensors. A first step to...

For people with physical disabilities, manual wheelchairs are essential enablers of mobility, participation in society, and a healthy lifestyle. Their most general design offers great flexibility and direct feedback, but has been described to be inefficient and demands good coordination of the upper extremities while critically influencing users’ a...

Robotic hand orthoses have the potential of supporting grasp function of people with sensorimotor impairments. To achieve lightweight and simple solutions, most devices focus on supporting only a subset of the functional abilities of the hand. This study investigates the effect of such a design trade-off in a wrist-constrained robotic hand orthosis...

Spinal cord injury (SCI) patients suffer from diverse gait deficits depending on the severity of their injury. Gait assessments can objectively track the progress during rehabilitation and support clinical decision making, but a comprehensive gait analysis requires far more complex setups and time-consuming protocols that are not feasible in the da...

Today's standard clinical practice to assess the walking ability of patients with neurological disorders during rehabilitation is based on simple gait tests such as the six-minute walking test (6MWT). Since the outcome of these tests is the average walking speed only, the aim of this work was to show that the application of movement sensors during...

Today's standard clinical practice to assess the walking ability of patients with neurological disorders during rehabilitation is based on simple gait tests such as the six-minute walking test (6MWT). Since the outcome of these tests is the average walking speed only, the aim of this work was to show that the application of movement sensors during...

Upper limb (UL) compensation is a common strategy of patients with a high spinal cord injury (SCI), i.e., tetraplegic patients, to perform activities of daily living (ADLs) despite their sensorimotor deficits. Currently, an objective and sensitive tool to assess UL compensation, which is applicable in the clinical routine and in the daily life of p...

Upper limb (UL) compensation is a common strategy of patients with a high spinal cord injury (SCI), i.e., tetraplegic patients, to perform activities of daily living (ADLs) despite their sensorimotor deficits. Currently, an objective and sensitive tool to assess UL compensation, which is applicable in the clinical routine and in the daily life of p...

Physical activity (PA) has been shown to have a positive influence on functional recovery in patients after a spinal cord injury (SCI). Hence, it can act as a confounder in clinical intervention studies. Wearable sensors are used to quantify PA in various neurological conditions. However, there is a lack of knowledge about the inter-day reliability...

Thin networks of high aspect ratio conductive nanowires can combine high electrical conductivity with excellent optical transparency, which has led to a widespread use of nanowires in transparent electrodes, transistors, sensors, and flexible and stretchable conductors. Although the material and application aspects of conductive nanowire films have...

Theoretical and in vivo neuroscience research suggests that functional information transfer within neuronal networks is influenced by circuit architecture. Due to the dynamic complexities of the brain, it remains a challenge to test the correlation between structure and function of a defined network. Engineering controlled neuronal networks in vitr...

Physiological communication between neurons is dependent on the exchange of neurotransmitters at the synapses. Although this chemical signal transmission targets specific receptors and allows for subtle adaptation of the action potential, in vitro neuroscience typically relies on electrical currents and potentials to stimulate neurons. The electric...

Physiological communication between neurons is dependent on the exchange of neurotransmitters at the synapses. Although such chemical signal transmission targets specific receptors and allows for subtle adaptation of the action potential, in vitro neuroscience typically relies on electrical currents and potentials to stimulate neurons. The electric...

Cells in vitro behave differently if cultured in a 2D or 3D environment. In spite of the continuous progress over the recent years, methods available for realizing 3D cultures of primary neurons are still fairly complex, limited in throughput and especially limited in compatibility with other techniques like multielectrode arrays (MEAs) for recordi...

Minimum toe clearance (MTC) occurs during a highly dynamic phase of the gait cycle and is associated with the highest risk of unintentional contact with obstacles or the ground. Age, cognitive function, attention and visual feedback affect foot clearance but how these factors interact to influence MTC control is not fully understood. We measured MT...

Presentation on "25th Annual Computational Neuroscience Meeting: CNS-2016 " BMC Neuroscience 17, 112-113 (2016).

Single-cell patterning represents a key approach to decouple and better understand the role and mechanisms of individual cells of a given population. In particular, the bottom-up approach of engineering neuronal circuits with controlled topology holds immense promises to perceive the relationships between connectivity and function. In order to acco...

The fundamental mechanisms of complex neural computation remain largely unknown, especially in respect to the characteristics of distinct neural circuits within the mammalian brain. The bottom-up approach of building well-defined neural networks with controlled topology has immense promise for improved reproducibility and increased target selectivi...

This study presents the effect of external electric current on the cell adhesive and mechanical properties of the C2C12 mouse myoblast cell line. Changes in cell morphology, viability, cytoskeleton, and focal adhesion structure were studied by standard staining protocols, while single-cell force spectroscopy based on the fluidic force microscopy te...

ICGenealogy: towards a common topology of neuronal ion channel function and genealogy in model and experiment Ion channels are fundamental constituents determining the function of single neurons and neuronal circuits. To understand their complex interactions, the field of computational modeling has proven essential: since its emergence, thousands...

Current technologies to monitor neuronal cultures in vitro are based on 2-dimensional (2D) multi-electrode arrays and cell cultures. The complexity of actual high-level neurobiological systems requires 3-dimensional (3D) cultures and 3D electrode arrays to improve our understanding of such systems. The realization calls for smart multilayer and pac...

A sequence-specific oligonucleotide detection method based on the tail-to-tail aggregation of functionalized gold nanoparticles in the presence of target analytes is presented together with its optimization and capabilities for detection of single nucleotide polymorphisms (SNPs). In this single-step method, capture probes are freely accessible for...

We report that stiffness gradients facilitate infiltration of cells through otherwise cell-impermeable hydrogel interfaces. By enabling the separation of hydrogel manufacturing and cell seeding, and by improving cell colonization of additively manufactured hydrogel elements, interfacial density gradients present a promising strategy to progress in...

By locally dispensing Poly-L-Lysine (PLL) molecules with a FluidFM onto a protein and cell resistant Poly-L-Lysine-grafted-Poly-Ethylene-Glycol (PLL-g-PEG) coated substrate, the antifouling layer can be replaced under the tip aperture by the cell adhesive PLL. We used this approach for guiding the adhesion and axonal outgrowth of embryonic hippocam...

We developed a topotactic strategy to grow BiTeCl single crystals. Structural characterization by means of X-ray diffraction was performed, and the high crystallinity of the material was proven. Measurements of the thermoelectrical coefficients electrical resistivity, thermoelectric power and thermal conductivity show an enhanced room temperature p...

We study the magneto-optical (MO) response of the polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3  T). Our first-principles calculations show that the enhanced MO r...

We study the magneto-optical (MO) response of polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being non-magnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (<3 T). By comparison with first-principles calculations, we show that such an...

The subtle interplay of randomness and quantum fluctuations at low temperatures gives rise to a plethora of unconventional phenomena in systems ranging from quantum magnets and correlated electron materials to ultracold atomic gases. Particularly strong disorder effects have been predicted to occur at zero-temperature quantum phase transitions. Her...

By applying external magnetic field the square-lattice antiferromagnet Ba2CoGe2O7 can be transformed to a chiral form, evidenced by large optical activity when the light is in resonance with spin excitations at sub-terahertz frequencies. We found that the magnetochiral effect, the absorption difference for the light beams propagating parallel and a...

Right- and left-handed circularly polarized light interact differently with electronic charges in chiral materials. This asymmetry generates the natural circular dichroism and gyrotropy, also known as the optical activity. Here we demonstrate that optical activity is not a privilege of the electronic charge excitations but it can also emerge for th...

Cyclodextrins are cyclic oligosaccharides that are able to form water-soluble inclusion complexes with small molecules. Because of their complexing ability, they are widely applied in food, pharmaceutical and chemical industries. In this paper we describe the development of a free web-service, Cyclodextrin KnowledgeBase: ( http://www.cyclodextrin.n...

A free web service (http://Cycloserver.organic.hu) was developed whereby cyclodextrin complexation of molecules can be estimated using molecular docking methodology. 98 various cyclodextrins were prepared in a dock-ready form on the server. Besides docking energy, the contact surface of the complex and dimerization energy of cyclodextrin hosts were...

A novel method for the simultaneous, high-resolution measurement of the specific heat c and the thermal conductivity κ is presented. A new experimental setup has been developed with special emphasis on the elimination of systematic errors arising from radiative heat loss. A self-consistent data evaluation method is implemented which takes the effec...

Over the last years, the use of bioinformatics tools such as molecular docking has become an essential part of research focused at prediction of the binding of small molecules to their target proteins. DockingServer offers a web-based, easy to use interface that handles all aspects of molecular docking from ligand and pro-tein set-up through result...

We have studied the bandwidth-temperature-magnetic-field phase diagram of RE0.55Sr0.45MnO3 colossal magnetoresistance manganites with ferromagnetic metal (FM) ground state. The bandwidth was controlled both via chemical substitution and hydrostatic pressure with a focus on the vicinity of the critical pressure p;{*} where the character of the zero-...

We have studied the bandwidth-temperature-magnetic field phase diagram of RE(0.55)Sr(0.45)MnO(3) colossal magnetoresistance manganites with ferromagnetic metallic (FM) ground state. The bandwidth (or equivalently the double exchange interaction) was controlled both via chemical substitution and hydrostatic pressure with a focus on the vicinity of t...

We present a systematic optical study for a bandwidth-controlled series of nearly half doped colossal magnetoresistive manganites RE$_{0.55}$AE$_{0.45}$MnO$_3$ (RE and AE being rare earth and alkaline earth ions, respectively) under the presence of quenched disorder over a broad temperature region $T=10-800$ K. The ground state of the compounds ran...

Knowledge of the relationship between protein's structure and its dynamic behavior is essential for understanding protein function. In this study, the description of a protein three-dimensional structure as a network of hydrogen bonding interactions (HB plot) is introduced as a tool for exploring protein structure and function. HB plot offers a sim...

BaVS3 is a moderately correlated d-electron system with a rich phase diagram. To construct the corresponding minimal electronic model, one has to decide which d-states are occupied, and to which extent. The ARPES experiment presented here shows that the behavior of BaVS3 is governed by the coexistence of wide-band (A1g) and narrow-band (twofold deg...

BaVS3 is a moderately correlated d-electron system with a rich phase diagram. To construct the corresponding minimal electronic model, one has to decide which d-states are occupied, and to which extent. The ARPES experiment presented here shows that the behavior of BaVS3 is governed by the coexistence of wide-band (A1g) and narrow-band (twofold deg...

The metal-insulator transition (MIT) of BaVS3 is suppressed under pressure, and above the critical pressure of pcr≈2 GPa the metallic phase is stabilized. We present the results of detailed magnetoresistivity measurements carried out at pressures near the critical value in magnetic fields up to B=12 T. We found that slightly below the critical pres...

BaVS3 is a moderately correlated d-electron system with a rich phase diagram. To construct the corresponding minimal electronic model, one has to decide which d-states are occupied, and to which extent. The ARPES experiment presented here shows that the behavior of BaVS3 is governed by the coexistence of wide-band (A_1g) and narrow-band (twofold de...

We study the high-pressure metallic phase of high-purity single crystals of BaVS$_3$ by measuring the temperature, pressure, and magnetic field dependence of the resistivity. Above the critical pressure of $p_{\rm cr}=1.97$GPa an extended non-Fermi liquid $p-T$ regime emerges with resistivity exponent $1.5 \le n<2$, crossing over to a FL only aroun...

In this work, a 2D computer model was created for the aggregation of rodlike particles, on the basis of a molecular-dynamic approach. With the help of the model, it is possible to visualize the motion of the aggregating particles, clearly and faithfully, offering the possibility of structural, kinetic, and dynamic analysis of the aggregation. The a...

Napjaink szilárdtestfizikai kutatásainak központi területét jelentik azok a kvantum-jelenségek, amelyekben az elektron töltése és spinje egyaránt lényeges szerepet játszik. A projekt keretében ilyen jelenségeket tanulmányoztunk hagyományos módszerekkel (ESR spektroszkópia, elektromos és mágneses mérések), valamint olyan új spektroszkópia eljárásokk...

A pályázat célkitűzése volt fázisátalakuláshoz közeli rendszerek paramétereinek finom hangolása hidrosztatikus nyomás alkalmazásával, valamint az egyes fázisok jellemzése nyomás alatt végzett elektromos és mágneses mérésekkel. A nyomás elsődleges hatása az átfedési integrálok módosítása, különösen az általunk vizsgált rendszerek irányított pályái e...

A projekt atomi és mesterséges atomi struktúrák illetve felületek, vékony rétegek vizsgálatát célozta ab initio illetve térelméleti módszerek együttes használatával, különös tekintettel a mágneses tulajdonságokra illetve az idő és spinfüggő nem egyensúlyi transzporttulajdonságokra. Céljaink között szerepelt egyfelől olyan nem egyensúlyi módszerek a...